1. Technical Field
The present invention relates to light emitting diodes with high heat-dissipation efficiency and light source modules having same.
2. Description of Related Art
A light emitting diode (LED) is one type of semiconductor light source, and the electrical and optical characteristics and life span thereof are greatly temperature-dependent. Generally, a high working temperature will cause a deterioration of an internal quantum efficiency of the LED and shorten the life span thereof. Furthermore, a resistance of a semiconductor has a negative temperature coefficient and tends to be reduced with an increase in the working temperature. Such a reduced resistance will correspondingly result in a larger current at a given voltage and the generation of excessive heat. If the excessive heat cannot be effectively dissipated, a phenomenon of heat accumulation will be difficult to avoid, and, accordingly, the deterioration of the LED can expect to be accelerated.
Referring to FIG. 5, a typical light emitting diode 100 includes a printed circuit board 101, a first electrode 102, a second electrode 103, a LED chip 104, and an encapsulant 105. The first electrode 102 and the second electrode 103 are parallelly positioned in the printed circuit board 101. The LED chip 104 is positioned on the first electrode 102 and wire bonded to the first electrode 102 and the second electrode 103. The encapsulant 105 is positioned on the printed circuit board 101 to package the LED chip 104. The excessive heat formed by the LED chip 104 is dissipated through the encapsulant 105 and the first electrode 102, but thermal conductivity of the encapsulant 105 and the first electrode 102 is not very well, such that the excessive heat cannot be effectively dissipated.
Therefore, what is needed is to provide a light emitting diode with high heat-dissipation efficiency and a light source module having same.